In the 1860s, he published banking, customs, industrial and financial statistics studies in journals and in the statistical and national economic publications of the Hungarian Academy of Sciences. After The Austro-Hungarian Compromise of 1867 he became the head of the Statistics Department of the Ministry of Agriculture, Industry and Trade. This office later became as the National Statistical Office established in 1871, in the organization of which Keleti played a significant role and was the first director of it until his death. He is known as the first designer and director of Hungarian statistical surveys. He organized the 1869 census and introduced the individual census sheet system for the 1880 census. He was one of the pioneers in the scientific cultivation of statistics in Hungary, and at the same time the organizer of the first industrial statistics.